Garden sculpture in Massachusetts turns out to be Mayan artifact

What last year was just an unusual ornament in a garden on the island of Martha's Vineyard is today back in Mexico. It turned out to be a 1,100-year-old white limestone sculpture from a Mayan shrine on the Yucatan Peninsula.

Police in Oak Bluffs uncovered the artifact during a routine investigation for stolen jewelry. When Peter Mathews, a research assistant at Harvard University's Peabody Museum, determined that the sculpture was Mexican, the case was turned over the United States Customs Service. The piece was confiscated and moved to Boston.

Professor Mathews says the monument was most likely the inner part of a door jamb. When the masonry collapsed around it, the rubble buried (and preserved) the lower part of the sculpture and exposed the top area to the elements, he says.

How did the artifact get to Martha's Vineyard? The owner was vague about where the piece came from. Customs officials say the man had it in his antique shop in Boston for several years before he took it to the island.

When Luz del Amo, the Mexican Foreign Ministry's director of cultural affairs , came to Boston to take the artifact home, she spoke of the continuing problem of plundered artifacts. She pointed to the number of items still being auctioned off and criticized the United States for less-than-complete cooperation.

''In the last three months, we have recorded the illegal sale abroad of more than 339 archaeological pieces (from Mexico),'' she said.

''In a high percentage of cases, everything points to the United States as the country of origin for most of the archaeological pieces destined for sale in other parts of the world - despite the Treaty of Cooperation signed by Mexico and this country in June 1971 calling for the recovery and return of plundered historic and cultural archaeological treasures,'' Mrs. del Amo said.